National legislation may require so-termed Lawful Interception (LI) to be possible in public communication networks such as mobile networks. Here, the term lawful interception generally refers to intercepting communication on a public communication network on request from a law enforcement agency for the purpose of screening the communication. Several approaches are known for intercepting communication data exchanged via mobile networks, e.g., as described in Aqsacom Document No. 100458, “LAWFUL INTERCEPTION FOR 3G AND 4G NETWORKS”, White paper, March 2010.
It may be desirable and/or required to also enable lawful interception of the communication data exchanged via D2D communication channels. For example, in the 3GPP TS 22.278 service requirements for the Evolved Packet System (EPS) it is stated that the EPS shall provide appropriate mechanisms to enable lawful intercept. EPS constitutes a core network architecture of LTE. A problem with enabling lawful interception of communication data exchanged via D2D communication channels is that such D2D communication takes place directly between the mobile devices, i.e., without transferring the communication data over a network element of the mobile network. It is therefore difficult for a Mobile Network Operator (MNO) to enable lawful interception of such communication data.
As a possible solution, a MNO may prevent the establishment of D2D communication between the mobile devices when a subscriber associated with one of these mobile devices is the subject of lawful interception. In such a case, when the MNO receives a request to establish a D2D communication channel from a user, and one of the participants in the D2D communication channel is the subject of lawful interception, the MNO may instead route the communication via a network element of mobile network that is equipped with lawful interception capabilities, e.g., a base station such as an eNodeB.